yamaha 60 alarm

I have a 60 hp yamaha. 2 cy. After idling out of the harbor, an alarm in the console went off. Eventually stopped, but we had power loss when we had run it for a few minutes at 2100 rpm. it continued at other rpm levels. Shut it down, restarted and seemed to run okay. Afraid to go for much of a test, because I don't want to have to come back on the kicker.